Lennox's motto is "I'll Defend". Kincaid and MacFarlane are both spawned by the Earl of Lennox, and use "This I'll Defend". Interestingly, I believe Kincaid and MacFarlane came by their mottos differently. Here is the MacFarlane badge:

I am not sure who Lennox or Kincaid are defending, but in the case of MacFarlane, notice that the demi-savage is pointing to an imperial crown with his left hand. The Regent, James, Earl of Moray, rewarded the MacFarlanes with the Clan's crest and motto for protecting him (and thus the crown) from his mother, Mary Queen of Scott's, in 1568.