What are the Hadiths in which the Prophet intended to enjoin something but did not do so; such as his saying: "Were it not that I would overburden my Ummah, I would have ordered them to use the Siwak with every prayer"?

The Prophet, peace and blessings be upon him, intended to legislate several matters but then abandoned them out of mercy for his Ummah. Among these were: delaying the Isha prayer, not staying behind from jihad, burning down houses of those who failed to attend congregational prayers, prohibiting intercourse with a breastfeeding woman (ghilah), not accepting gifts except from a Qurayshi, Ansari, Thaqafi, or Dawsī, in addition to the matter of the siwak (tooth-stick).