Halakhah zu Schemot 20:23

To not take steps on the altar: To not ascend the altar with stairs, so that he not make large steps in his going up - as it is stated (Exodus 20:23), "And you shall not ascend My altar by stairs, that your nakedness not be exposed upon it." Rather, when he ascends there, he should walk slowly and with awe, [placing] his heel in front of his toe. And so is it said in the Mekhilta d'Rabbi Yishmael 20:23.