Walikum Salam
yes SA' holds great significance in Islam - read the follows
Fiqh-us-Sunnah Fiqh 3.88a
The Amount of Zakat ul-Fitr
The required amount of zakat ul-fitr is one sa' of wheat, barley, raisins, dry cottage cheese (aqit), rice, corn, or similar items considered as basic foods (qut). Abu Hanifah made it permissible to set aside, as a zakat ul-fitr, an equivalent value and also said that if the payer pays in wheat, one-half of a sa' would be sufficient. Abu Sa'id al-Khudri reported: "We used to give on behalf of every child, old person, freeman, and slave during the lifetime of the Messenger of Allah, upon whom be peace, one sa' of food, or one sa' of dried cottage cheese, or one sa' of barley, or one sa' of dates, or one sa' of raisins as zakat ul-fitr. We continued to do so until Mu'awiyyah came to us to perform pilgrimage (hajj) or a minor pilgrimage ( 'umrah). He then addressed the people from the pulpit and said to them: 'I see that two mudds of wheat of Syria equals one sa' of dates.' The people accepted that." However, Abu Sa'id contended: "I would continue to give as I used to give, namely, one sa' as long as I live." This is related by most hadith narrators. At-Tirmidhi remarks: "Some of the scholars gave one sa' from every charitable item [which is accepted as a sound practice]." Ash-Shaf'i and Ishaq sustain this view but some other scholars gave one sa' from every charitable item except wheat, of which only half a sa' would be sufficient. This is the saying of Sufyan, Ibn al-Mubarak, and the scholars of Kufah.