Lord Krishna uses many illustrative examples (upamaana) as part of His teaching in the Gita. Many of these have become almost canonical in Vedantic teminology. Here are some of them, with Swami Gambhirananda's translation, and my [by ramakrishna ]
jiirNaani yathaa vihaaya
navaani gR^ihNaati naro.aparaaNi .
tathaa shariiraaNi vihaaya jiirNaani
anyaani sa.nyaati navaani dehii .. 2.22..
As after rejecting worn-out clothes a man takes up other new ones, likewise after rejecting worn-out bodies the embodied one unites with other new ones.
[Ephemerality of the Body-Mind complex and the independence of the Self with respect to them.]
udapaane sarvataH saMplutodake .
taavaansarveshhu vedeshhu braahmaNasya vijaanataH .. 2.46..
A Brahmana with realization has that much utility in all the Vedas as a man has in a well when there is a flood all around.
[Relevance (or rather non-relevance) of karma and "the path" to one who is realized.]
sa.nharate chaayaM kuurmo.aN^gaaniiva sarvashaH .
indriyaaNiindriyaarthe.abhyastasya praGYaa pratishhThitaa .. 2.58..
And when this one fully withdraws the senses from the objects of the senses, as a tortoise wholly (withdraws) the limbs, then his wisdom remains established.
[The nature of one who has so little association with the senses that he can control to the direction in which they move, including shutting them down or reversing their direction (reversing their direction has its source in kaTha.).]
hi charataaM yanmano.anuvidhiiyate .
tadasya harati praGYaaM vaayurnaavamivaambhasi .. 2.67..
For, the mind which follows in the wake of the wandering senses, that (mind) carries away his wisdom like the mind (diverting) a boat on the waters.
[The mind getting carried away by its association with senses.]
samudramaapaH pravishanti yadvat.h .
tadvatkaamaa yaM pravishanti sarve
sa shaantimaapnoti na kaamakaamii .. 2.70..
That man attains peace into whom all desires enter in the same way as the waters flow into a sea that remains unchanged (even) when being filled up from all sides. Not so one who is desirous of objects.
[The sense association is not cared for, by the Jivanmukta.]
vahniryathaadarsho malena cha .
yatholbenaavR^ito garbhastathaa tenedamaavR^itam.h .. 3.38..
As fire is enveloped by smoke, as a mirror by dirt, and as a foetus remains enclosed in the womb, so in this (Self-knowledge) shrouded by that (desire).
[The three examples for how kaama shrouds the fire of Self-knowledge. The three are at different levels. The first one is easy to remove and goes away in a short time, the second one goes away with right effort in a short time, while the third one takes longer time and more right effort. The effort the three are the wind, water and mother.]
GYaanaagniH sarvakarmaaNi bhasmasaatkurute tathaa .. 4.37..
O Arjuna, as a blazing fire reduces pieces of wood to ashes, similarly the fire of Knowledge reduces all actions to ashes.
[Only GYaana can burn the association with karma.]
karmaaNi saN^ga.n tyaktvaa karoti yaH .
lipyate na sa paapena padmapatramivaambhasaa .. 5.10..
One who acts by dedicating actions to Brahman and by renouncing attachment, he does not become polluted by sin, just as a lotus leaf is not by water.
[The senses and their associations do not touch the person who is intensely dedicated to the path..]
hi manaH kR^ishhNa pramaathi balavad.h dR^iDham.h .
tasyaahaM nigrahaM manye vaayoriva sudushhkaram.h .. 6.34..
For, O Krsna, the mind is unsteady, turbulent, strong and obstinate. I consider its control to be as greatly difficult as of the wind.
[How can one control the vritti, which is like the wind? The next verses offer the method. The key is perseverance and detachment.]
parataraM naanyatki.nchidasti dhana.njaya .
mayi sarvamidaM protaM suutre maNigaNaa iva .. 7.7..
O Dhananjaya, there is nothing else whatsoever higher than Myself. All this is strung on Me like pearls on a string.
[The immanence of Brahman.]
nitya.n vaayuH sarvatrago mahaan.h .
tathaa sarvaaNi bhuutaani matsthaaniityupadhaaraya .. 9.6..
Understand thus that just as the voluminous wind moving everywhere is ever present in space, similarly all beings abide in Me.
[Immanence of Brahman.]
shariiraM kaunteya kshetramityabhidhiiyate .
etadyo vetti taM praahuH kshetraGYa iti tadvidaH .. 13.2..
O son of Kunti, this body is referred to as the 'field'. Those who are versed in this call him who is conscious of it as the 'knower of the field'.
[The field is a field only if properly cultivated with the right goal in mind. Further, the "seen" is a perishable entity and hence ephemeral. The seer, on the other hand is eternal.]
sarvagataM saukshmyaadaakaashaM nopalipyate .
sarvatraavasthito dehe tathaatmaa nopalipyate .. 13.33..
As the all-pervading space is not defiled, because of its subtlety, similarly the Self, present everywhere in the body, is not defiled.
[The immanence of the Self. Also see 9.6 above.]
prakaashayatyekaH kR^itsna.n lokamimaM raviH .
kshetra.n kshetrii tathaa kR^itsnaM prakaashayati bhaarata ..
As the single sun illumines this whole world, similarly, O descendant of the Bharata dynasty, the Knower of the field illumines the whole field.
[The awareness of everything owes to the Self. Refer to verses 15.6 (na tatbhasayate suuryo ...) and 15.12 (yadaadityagatam tejo ...).]
chhandaa.nsi yasya parNaani yasta.n veda sa vedavit.h .. 15.1..
They say that the fig Tree, which has its roots upward and the branches downward, and of which the Vedas are the leaves, is imperishable. He who realizes it is knower of the Vedas.
[The classic illustration of the fig tree, adapted from kaTha Upanishad.]
guNapravR^iddhaa vishhayapravaalaaH .
karmaanubandhiini manushhyaloke .. 15.2..
The branches of that (Tree), extending down-wards and upwards, are strengthened by the qualities and have sense-objects as their shoots. And the roots, which are followed by actions, spread down-wards in the human world.
[Upside-ness of the tree of Samsara.]
yadavaapnoti yachchaapyutkraamatiishvaraH .
gR^ihitvaitaani sa.nyaati vaayurga.ndhaanivaashayaat.h .. 15.8..
When the master leaves it and even when he assumes a body, he departs taking these, as wind (carries away) odours from their receptacles.
[vaasanas, sukshma and kaaraNas exist beyond death. This keeps happening till the jIvatva dies off and the aatmatva dawns.]
karma kaunteya sadoshhamapi na tyajet.h .
sarvaarambhaa hi doshheNa dhuumenaagnirivaavR^itaaH .. 18.48..
O son of Kunti, one should not give up the duty to which one is born, even though it be faulty. For all undertakings are surrounded with evil, as fire is with smoke.
[The undertakings which are egoistic in nature lead to further bondage. Also see 3.38 above.]
sarvabhuutaanaa.n hR^iddeshe.arjuna tishhThati .
bhraamayansarvabhuutaani yantraaruuDhaani maayayaa .. 18.61..
O Arjuna, the Lord resides in the region of the heart of all creatures, revolving through Maya all the creatures (as though) mounted on a machine!
[The immanence of the Self. Refer to 7.7 above. Also the working of the Ishvara and Maya locus with the jIva. Also refer to 15.15 (sarvasya chaaham hR^idi sannivishhTo...)]
These are taken from an introductory section of Swami Sri Vidyaprakasananda Giri's "Gita Makarandam", a very well known translation of Gita in Telugu speaking people. The book is availableonline at Telugu Bhakti Pages.