Which preposition to use with yf

in Occurrences 1%

Yf in the voyage he doe chance to [MS. doe]

than Occurrences 1%

free His gylted craft and gloyre in content Gay thynges I made eke, yf than lust to see Go loke the Code also the dygestes thre The bookes of lawe and of physyke good Of ornate speche there spryngeth up the flood.

Which preposition to use with  yf