Thirukkural

Kural - 781
What so hard for men to gain as friendship true?
What so sure defence 'gainst all that foe can do?
What things are there so difficult to acquire as friendship ? What guards are there so difficult to break through by the efforts (of one's foes) ?

Kural - 782
Friendship with men fulfilled of good Waxes like the crescent moon;
Friendship with men of foolish mood, Like the full orb, waneth soon.
The friendship of the wise waxes like the new moon; (but) that of fools wanes like the full moon.

Kural - 783
Learned scroll the more you ponder, Sweeter grows the mental food;
So the heart by use grows fonder, Bound in friendship with the good.
Like learning, the friendship of the noble, the more it is cultivated, the more delightful does it become.

Kural - 784
Nor for laughter only friendship all the pleasant day,
But for strokes of sharp reproving, when from right you stray.
Friendship is to be practised not for the purpose of laughing but for that of being beforehand in giving one another sharp rebukes in case of transgression.

Kural - 785
Not association constant, not affection's token bind;
'Tis the unison of feeling friends unites of kindred mind.
Living together and holding frequent intercourse are not necessary (for friendship); (mutual) understanding can alone create a claim for it.

Kural - 786
Not the face's smile of welcome shows the friend sincere,
But the heart's rejoicing gladness when the friend is near.
The love that dwells (merely in the smiles of the face is not friendship; (but) that which dwells deep in the smiles of the heart is true friendship.

Kural - 787
Friendship from ruin saves, in way of virtue keeps;
In troublous time, it weeps with him who weeps.
(True) friendship turns aside from evil (ways) makes (him) walk in the (good) way, and, in case of loss if shares his sorrow (with him).

Kural - 788
As hand of him whose vesture slips away,
Friendship at once the coming grief will stay.
(True) friendship hastens to the rescue of the afflicted (as readily) as the hand of one whose garment is loosened (before an assembly).

Kural - 789
And where is friendship's royal seat? In stable mind,
Where friend in every time of need support may find.
Friendship may be said to be on its throne when it possesses the power of supporting one at all times and under all circumstances, (in the practice or virtue and wealth).

Kural - 790
Mean is the friendship that men blazon forth,
'He's thus to me' and 'such to him my worth'.
Though friends may praise one another saying, "He is so intimate with us, and we so much (with him)"; (still) such friendship will appear mean.