Θησεῖον
From LSJ
ἃ γὰρ δεῖ μαθόντας ποιεῖν, ταῦτα ποιοῦντες μανθάνομεν → what we have to learn to do we learn by doing
English (LSJ)
τό,
A temple of Theseus, a sanctuary (ἄσυλον) for criminals and slaves, Ar.Eq.1312,Fr.567:—also Θησέον, Pherecr.49 (cf. Et.Gen.). II Θησεῖα, τά, festival of Theseus, Ar.Pl.627:—also Θησέα, SIG1029.78 (iv B.C.). III θησεῖον, τό, holewort, Corydalis densiflora, Thphr.HP7.12.3, Plin.HN21.107.