“What was the “spirit of the law” in not working / rendering aid on the Sabbath?”
The letter of the law was do no work on the Sabbath. The spirit of the law was keeping the Sabbath holy by loving and serving a neighbor in need. The Good Samaritan kept the spirit of the Sabbath.
The ‘spirit’ you mention and the letter of that Sabbath law are totally unlinked, which is why I asked you the question.
How can the disobedience of a supposedly divine law be ‘holy’?