to examine into judicially, to find out
詧 centers on careful, formal examination to uncover truth: investigating judicially or finding out facts through scrutiny.
詧 is a rare character combining 言 (speech, words) with an upper component that may be a variant of 祭 or a related phonetic element. The exact historical development is uncertain, but the structure suggests using words to examine or investigate.
The bottom 言 (words) under a roof-like top suggests formal speech used in a court or inquiry. Picture a judge using words to examine evidence and find out the truth.
For サツ, imagine a detective examining clues and suddenly saying 'That's it!' — the 'tsu' sound in 'That's' cues サツ while the investigation scene fits the meaning.