About Upatissa (Sāriputta)
Upatissa Sutta  (SN 21:2)

Near Sāvatthī. There Ven. Sāriputta addressed the monks: “Friends!”

“Yes, friend,” the monks responded.

Ven. Sāriputta said, “Friends, just now as I was withdrawn in seclusion, this train of thought arose to my awareness: ‘Is there anything in the world with whose change or alteration there would arise within me sorrow, lamentation, pain, distress, & despair?’ Then the thought occurred to me: ‘There is nothing in the world with whose change or alteration there would arise within me sorrow, lamentation, pain, distress, & despair.’”

When this was said, Ven. Ānanda said to Ven. Sāriputta, “Sāriputta my friend, even if there were change & alteration in the Teacher would there arise within you no sorrow, lamentation, pain, distress, or despair?”

“Even if there were change & alteration in the Teacher, my friend, there would arise within me no sorrow, lamentation, pain, distress, or despair. Still, I would have this thought: ‘What a great being, of great might, of great prowess, has disappeared! For if the Blessed One were to remain for a long time, that would be for the benefit of many people, for the happiness of many people, out of sympathy for the world; for the welfare, benefit, & happiness of human & divine beings.’”

“Surely,” (said Ven. Ānanda,) “it’s because Ven. Sāriputta’s I-making & mine-making and obsession with conceit have long been well uprooted that even if there were change & alteration in the Teacher, there would arise within him no sorrow, lamentation, pain, distress, or despair.”

See also: DN 16; SN 47:13; AN 5:49