Behold, a virgin shall be with child, and shall bring forth a son, and they shall call his name Emmanuel, which being interpreted is, God with us". The feast of Tabernacles is to commemorate when Yehovah "tabernacled" with Israel in the wilderness.
Jesus came not only to bring salvation, but to also fulfill each of the seven feasts (appointed times) given to Israel. He first fulfilled the last feast, the feast of tabernacles, before fulfilling the first feast, the feast of Passover, because He was to be the “first and the last”, and the “beginning and the end”.