godsend

[god-send] /ˈgɒdˌsɛnd/
noun
1.
an unexpected thing or event that is particularly welcome and timely, as if sent by God.
Origin
1805-15; earlier God's send, variant (by influence of send1) of God's sond or sand, Middle English Godes sand (sand Old English: message, service)
British Dictionary definitions for godsend

godsend

/ˈɡɒdˌsɛnd/
noun
1.
a person or thing that comes unexpectedly but is particularly welcome
Word Origin
C19: changed from C17 God's send, alteration of goddes sand God's message, from Old English sand; see send1
Word Origin and History for godsend
n.

1814, "a shipwreck" (from the perspective of people living along the coast), from Middle English Godes sonde (c.1200) "God's messenger; what God sends, gift from God, happening caused by God," from god + Middle English sonde "that which is sent, message," from Old English sand, from sendan (see send (v.)). Sense of "happy chance" is from 1831.