What is the ruling on one who looks at women, saying the first glance is permissible, and then averts his gaze?

Lowering the gaze is obligatory regarding forbidden things and everything from which temptation is feared. The first glance that occurs suddenly and unintentionally carries no sin, but it is not permissible to intentionally look afterwards, and one must avert the gaze, as the Prophet, peace and blessings be upon him, said: "O Ali, do not follow a glance with another glance, for you are allowed the first, but not the last." And his saying, peace and blessings be upon him, regarding a sudden glance: "He commanded me to avert my gaze."