Messi didn't play until matchday 5. He started for the first time on matchday 6 and missed matchday 7. He returned in matchday 8, scoring his first league goal of the season. And he hasn't stopped scoring.
He scored another against Eibar, 2 against Valladolid and 3 against Celta for a grand total of 8 goals. 8 goals in just 5 matchdays, an unstoppable rhythm that few can match.
He will look to score in the 6th consecutive matchday against Leganés. But even if it's stunning, it's far from his best scoring streak.
This happened in 2012-13 when he scored in 21 matches in a row. This season he would have done it in 7 in all competitions, but the goalless draw against Slavia deprived him of this. He will have to settle with continuing to score in the league.