The final verse of Parashat Yitro introduces a prohibition against climbing to the altar by stairs: “ve-lo ta’aleh be-ma’alot al mizbechi” (20:23). The reason for this law, as the Torah explains, is “asher lo tigaleh ervatekha alav” – walking up steps while dressed in a robe results in exposing the private area of the body, which would be inappropriate when performing the service in the Beit Ha-mikdash. Due to this prohibition, the altar was constructed with a ramp that led to the top surface of the altar, and the kohanim would walk up in the ramp, instead of walking up steps. The details of the ramp’s construction are presented by the Mishna in Masekhet Middot (3:3).
The Talmud Yerushalmi, in Masekhet Berakhot (1:1), states that this law not only requires kohanim to ascend via a ramp instead of stairs, but also forbids them from taking long strides as they walk up the ramp. Specifically, the Yerushalmi comments, the kohanim were required to walk up the ramp in a manner of “gudal be-tzad akeiv” – heel to toe. With each step, the foot moving forward should not be placed further than the place where its heel would be parallel to the other foot’s toes. Taking wider steps would violate the Torah’s prohibition against exposing one’s private area while walking up to the altar. This requirement is also mentioned by one opinion cited in the Mekhilta (here in Parashat Yitro), by the Rambam, in Sefer Ha-mitzvot (lo ta’aseh 80), and by the Sefer Ha-chinukh (41).
Several Rishonim addressed the question of how to reconcile this requirement with the Mishna’s description in Masekhet Yoma (22a) of how the kohanim would race up the ramp to the altar. The original system for determining which kohen would receive the privilege of performing the terumat ha-deshen ritual – cleaning the top of the altar, the first ritual performed in the Mikdash each morning – was that the kohen who won the race and reached the top first would be given this privilege. (Later, it was decided to conduct a lottery, instead, as kohanim were getting hurt when racing up the altar.) It stands to reason that the kohanim racing up the altar took as large strides as possible in order to reach the top as quickly as they could, and, moreover, it is very difficult, if not impossible, to run in a manner of “gudal be-tzad akeiv.” How, then, was this race halakhically acceptable, in light of the requirement to take small, modest steps while ascending the altar? Indeed, some, such as Malbim, claimed that this account of the kohanim racing proves that the view requiring “gudal be-tzad akeiv” was not accepted, and for this reason, the Rambam omits this requirement in his Mishneh Torah (even though he does mention it in Sefer Ha-mitzvot).
Others, however, suggested ways to reconcile the Mishna’s account with the requirement of “gudal be-tzad akeiv.” One relatively simple possibility is proposed by Rav Chaim Elazary, in his Netivei Chayim. He writes that running might be permissible because there is no discernible pause between steps. When a person walks normally, there is a moment between each step when his legs are apart, thus disrespectfully exposing his private area. But when a person runs, and especially if he races and tries to reach the top as fast as possible, his legs move so quickly that the moment when his legs are spread apart cannot be discerned. Therefore, Rav Elazary suggests, Halakha might perhaps distinguish between walking up the altar, which must be done in a manner of “gudal be-tzad akeiv,” and running up the altar, which is entirely permissible.