The simplest inference is that Luke simply cribbed what he liked directly from Matthew, and omitted what he didn't. There is not a hint of evidence for unattes

The simplest inference is that Luke simply cribbed what he liked directly from Matthew, and omitted what he didn't. There is not a hint of evidence for unattested "sources" beyond their fevered imaginations. Making shit up was just how the stuff was produced, at the time, as illustrated by the (literally!) dozens of other "gospels" and forged epistles from the same period.