There are two מזבחות:
1) מזבח אדמה which is a reference to involvement in direct holiness, תורה ומצוות which is why it is a certainty.
2) מזבח אבנים which is a reference to the involvement in Klipa, and it is therefor written as a condition “If” one (needs) to involve himself in correcting this involvement, it will reveal greater light. MP3
