I have heard that on one occasion the Blessed One was staying near Sāvatthī at Jeta's Grove, Anāthapiṇḍika's monastery. And on that occasion Ven. Saṅgāmaji had arrived in Sāvatthī to see the Blessed One. His former wife heard, "Master Saṅgāmaji, they say, has arrived in Sāvatthī." Taking her small child, she went to Jeta's Grove. On that occasion Ven. Saṅgāmaji was sitting at the root of a tree for the day's abiding. His former wife went to him and, on arrival, said to him, "Look after me, contemplative — (a woman) with a little son." When this was said, Ven. Saṅgāmaji remained silent. A second time... A third time, his former wife said to him, "Look after me, contemplative — (a woman) with a little son." A third time, Ven. Saṅgāmaji remained silent.
Then his former wife, taking the baby and leaving him in front of Ven. Saṅgāmaji, went away, saying, "That's your son, contemplative. Look after him."
Then Ven. Saṅgāmaji neither looked at the child nor spoke to him. His wife, after going not far away, was looking back and saw Ven. Saṅgāmaji neither looking at the child nor speaking to him. On seeing this, the thought occurred to her, "The contemplative doesn't even care about his son." Returning from there and taking the child, she left.
The Blessed One — with his divine eye, purified and surpassing the human — saw Ven. Saṅgāmaji's former wife misbehaving in that way.
Then, on realizing the significance of that, the Blessed One on that occasion exclaimed:
At her coming,
he didn't delight;
at her leaving,
he didn't grieve.
A victor in battle, freed from the tie:
He's what I call a brahman.
"Saṅgāmaji Sutta: Saṅgāmaji" (Ud 1.8), translated from the Pali by Thanissaro Bhikkhu
I understand that Ven. Saṅgāmaji, now a monk, should not and did not delight upon seeing his wife nor grieve upon her leaving.
But abandoning his small child?? This seems irresponsible.
What was Ven. Saṅgāmaji's socio-economic status before he ordained? Who was looking after his wife and child after he left for the monkhood?