Hello Venerable Pesala,
Could it be that he wasn't aware of it? I have been taught that Omniscience doesn't mean knowing everything, always, and at all times.
Omniscience is 1 : having infinite awareness, understanding, and insight 2 : possessed of universal or complete knowledge. Omniscience doesn't mean having psychic powers ~ many beings attain those. The Buddha explains below just what omniscience means in the context of a Sammasambuddha.
The omniscience of the Buddha is covered in the suttas ~
Majjhima Nikaya 71 Tevijjavacchagotta Sutta 'To Vacchagotta on the
Threefold True Knowledge'
"Venerable sir, I have heard this: "The recluse Gotama claims to be
omniscient and all-seeing, to have complete knowledge and vision
thus: "Whether I am walking or standing or sleeping or awake,
knowledge and vision are continuously and uninterruptedly present to
me." Venerable sir, do those who speak thus say what has been said
by the Blessed One, and not misrepresent him with what is contrary to
fact? Do they explain in accordance with the Dhamma in such a way
that nothing which provides a ground for censure can be legitimately
deduced from their assertion?"
"Vaccha, those who say thus do not say what has been said by me, but
misrepresent me with what is untrue and contrary to fact."
note 714 says: MA explains that even though part of the statement is
valid, the Buddha rejects the entire statement because of the portion
that is invalid. The part of the statement that is valid is the
assertion that the Buddha is omniscient and all-seeing; the part that
is excessive is the assertion that knowledge and vision are
continuously present to him. According to the Theravada tradition
the Buddha is omniscient in the sense that all knowable things are
potentially accessible to him. He cannot, however, know everything
simultaneously and must advert to whatever he wishes to know.
At MN 90.8 the Buddha says that it is possible to know and see all, though
not simultaneously, and at AN 4.24/ii.24 he claims to know all that
can be seen, heard, sensed, and cognised, which is understood by the
Theravada tradition as an assertion of omniscience in the qualified
sense. See too in this connection Miln 102-7.
Majjhima Nikaya 90 Kannakatthala Sutta 'At Kannakatthala'
5. "Then King Pasenadi of Kosala said to the Blessed One: 'Venerable
sir, I have heard this: 'The recluse Gotama says "There is no recluse
or brahmin who is omniscient and all-seeing, who can claim to have
complete knowledge and vision; that is not possible." 'Venerable
sir, do those who speak thus say what has been said by the Blessed
One, and not misrepresent him with what is contrary to fact? Do they
explain in accordance with the Dhamma in such a way that nothing that
provides a ground for censure can be legitimately deduced from their
"Great King, those who speak thus do not say what has been said by
me, but misrepresent me with what is untrue and contrary to
"I recall having actually made the utterance in this way, great
king. 'There is no recluse or brahmin who knows all, who sees all,
simultaneously; that is not possible'.
note 846 says: MA: There is no one who can know and see all - past,
present and future - with one act of mental adverting, with one act of
consciousness; thus this problem is discussed in terms of a single
act of consciousness (ekacitta). On the question of the kind of
omniscience the Theravada tradition attributes to the Buddha, see n.
A few old threads (at E-sangha) discussing the subject -
In the thread "Does an Arhat know everything?"
metta and respect
---The trouble is that you think you have time---
---Worry is the Interest, paid in advance, on a debt you may never owe---
---It's not what happens to you in life that is important ~ it's what you do with it ---