To the holy his ways are straight, just as they are obstacles to the wicked: The picture here is of a trail or path. God has trails he wants us to walk. If we are holy (Good News Translation “devout” or “the Lord’s people”), they are easy, straight. But God makes those trails rough for wicked people to walk. There are obstacles, barriers, traps. Contemporary English Version has a good model for this verse:

• God lets his people walk
on a straight pathway,
but those who reject his laws
will find that their path
is lined with hidden traps.

Quoted with permission from Bullard, Roger A. and Hatton, Howard A. A Handbook on Sirach. (UBS Helps for Translators). New York: UBS, 2008. For this and other handbooks for translators see here.