וַיִּ֧בֶן שָׁא֛וּל מִזְבֵּ֖חַ לַֽיהוָ֑ה אֹת֣וֹ הֵחֵ֔ל לִבְנ֥וֹת מִזְבֵּ֖חַ לַֽיהוָֽה׃ (פ)
And Saul built an altar unto the LORD; the same was the first altar that he built unto the LORD.
Read halakhic rulings (Jewish law) on I Samuel 14:35: and classical halakhic sources.