The gemara5 tells of a story where a person rode a horse on Shabbos during the period of the Greek occupation of Eretz Yisrael. They brought him to Beis Din and he was stoned as if he violated Shabbos biblically. This was not done because he deserved it since it was only a rabbinic prohibition, not a capital offense. This was done because the times demanded it.
Why did this happen to this person that never happened to anyone else, that he got stoned for a rabbinic prohibition? This never happened before until this era?
The Rema Mipano6 explains that this person was a gilgul of Tzelafchad7 who was the mekoshaish in the desert. Therefore when he transgressed a rabbinic prohibition he was punished stringently and that's how he received atonement.
Now, the gemara tells of a pious man where a hole was breached in the fence of his field and he decided to fence in the breach. He then remembered it was Shabbos and he refrained from fencing it. A miracle was performed and a caper tree, called a צלף, grew in the breach and it provided his livelihood and the livelihoods of the members of his house.9 This story begs the question: Why was this pious man was stringent on himself since such thoughts are permitted on Shabbos?10
The answer is because this person was a gilgul of Tzelafchad. The Arizal11 says that what grew was specifically a צלף caper tree, which is חד, sharp, as it was to hint that this was a gilgul of צלפחד which is comprised of the words צלף חד a sharp caper tree.