Because thou hast been my help, therefore in the shadow of thy wings will I rejoice. Therefore in the shadow of thy wings - I will get into the very secret of thy presence, into the holy of holies, to the mercy-seat, over which the cherubs extend their wings. If the psalmist does not allude to the overshadowing of the mercy-seat by the extended wings of the cherubim, he may have in view, as a metaphor, the young of fowls, seeking shelter, protection, and warmth under the wings of their mothers. See the same metaphor, Psalms 61:4 (note). When a bird of prey appears, the chickens will, by natural instinct, run under the wings of their mothers for protection.
The old Psalter translates, And in hiling of thi wenges I sall joy. The paraphrase is curious. "Thou art my helper, in perels; and I can joy in gode dedes in thi hiling, (covering), for I am thi bride, (bird), and if thou hil (cover) me noght, the glede (kite) will rawis me, (carry me away.")