ἅψας [3 verses] (part sg aor act masc nom) "When he has lighted" is hapto, which means to " fasten or bind to", "join", metaph. "engage in", "undertake", "begin", "set to work", "lay hands on",  "touch", "affect",  "grasp with the senses", "perceive", "have intercourse with a woman", "come up to", "reach", "overtake", "make use of", "avail oneself of", "kindle", and "set on fire". - The Greek verb translated as  "when he has lighted" means primarily "to join" or "touch"and "set to work," with a lot of the same special uses as "join" in English.  However, it also means "to kindle," and "set on fire." It is unrelated to the word "light." Jesus uses it three times, all in Luke, to mean "to light."