144,000 from Each Tribe

144,000 from the twelve tribes were sealed (in the Book of Revelation). There were 288 singers in David's tabernacle. 144 is half of 288. Does the figure of 144,000 therefore symbolize that it was only a remnant of Israel that was sealed? And yet 144=12x12. It was therefore a complete number, in its own right. The election according to grace hath obtained it, and the rest were hardened. And so [in this manner?] all Israel shall be saved [i.e., the true Israel amongst the Israelites].