ἴσασι

From LSJ

μακάριοι οἱ πτωχοί τῷ πνεύματι ὄτι αὐτῶν ἐστὶν ἡ βασιλεία τῶν οὐρανῶν → blessed are the poor in spirit, for theirs is the kingdom of heaven (Matthew 5:3)

Source

French (Bailly abrégé)

3ᵉ pl. prés. ind. de ἴσημι.

Russian (Dvoretsky)

ἴσασι: 3 л. pl. pf. к *εἴδω.