Proverb
There are friends who pretend to be friends, but there is a friend who sticks closer than a brother.
Geogre Du Maurier
In politics, your friends are false, but your enemies are real.
Mahabharata
The Yaksa asked, -'What is the soul of man? Who is that friend bestowed on man by the gods? What is man's chief support? And what also is his chief refuge?' Yudhisthira answered,—"The son is a man's soul: the wife is the friend bestowed on man by the gods; the clouds are his chief support; and gift is his chief refuge.' 313. 71-72 Maha Vana.
The Pachatantra
Who are friends? What’s the cost, and what’s the gain? Time and again, one should ponder over these.