it works from attacks too, but its tricky
u need an elemnetal modifier to your attack to proc it, futhermore u need for example fire aliment to be your first aliment on your attack and fire dmg has to be your highest dmg from this attack - so its simply not profitable with bleeding edge, as u want to play full material damage
option is to proc it with warpath from fire modifier for this skill, but here we go again, there is another trick, when u use a beacon for the lost passive which is must have +35% dps, then ur main aliment for warpath becomes sacred dmg and it doeasnt proc ancient fervour, the option is to put fire gems to your weapon but i dont believe its worth it, the second option is to play only 25% dmg from beacon for the lost passive and not take this additional 10%, then for me sared dmg for warpath becomes second aliment and burn aliment as first, but once again i believe +35% from beacon is a must have and not worth resign from it to proc ancient fervour