The weakest of people is the one who cannot make brothers (friends); weaker still is the one who loses the friend he has made.
أعجز الناس من عجز عن اكتساب الإخوان، وأعجز منه من ضيّع من ظفر به منهم
A'cezü'n-nâsi men aceze ani'ktisâbi'l-ihvân, ve a'cezü minhü men dayyaa men zafira bihî minhüm
Ali, Nahj al-Balagha, saying 12 (Subhi Salih edition, p. 470; saying 11 in the Abduh edition). Nahj al-Balagha is a compilation by al-Sharif al-Radi (d. 1015), without chains of transmission.
Ali does not measure weakness by strength.
He measures it by the heart.
The one who cannot make friends is left alone.
But the one who loses the friend he has made
has found something and let it fall from his hand.
The second is heavier.
For the road was open, the door ajar.