From Lasker's first lecture, on development: one of the “well known little games” he gives without names, in which a careless move and a premature Bishop sally are punished at once by the classic Légall mating pattern — White sacrifices the Queen and mates with the minor pieces. From Common Sense in Chess (1896).
3…h6So far, with the exception of the last move, Black has played quite well. He has opened lines for his two Bishops and the Queen, and now should bring out his Q Kt to B 3. Instead of that, afraid of some premature attack, he quite unnecessarily makes a move that does not give additional force to any of his pieces.
4…Bg4A mistake. The Knights should be first developed, then the Bishops.
Emanuel Lasker, Common Sense in Chess (1896) · Public domain · source