A.T. Robertson Commentary Matthew 14:7

"Whereupon he promised with an oath to give her whatsoever she should ask." — Matthew 14:7 (ASV)

Promised with an oath (μετα ορκου ωμολογησεν). Literally, "confessed with an oath." For this verb in the sense of promise, see Ac 7:17. Note middle voice of αιτησητα (ask for herself). Cf. Esther 5:3; 7:2.