The first High Commissioner of Palestine was appointed by the Brittish Mandatory authorities between the two World Wars. A semi-observant Jew, Sir Herbert Samuels was known to be careful not to violate Shabbos publicly. Every Shabbos, he would walk the long distance from his home on Augusta Victoria on
To the surprise of many, when Sir Herbert first met the Rav of Yerushalayim, Rav Yosef Chaim Sonnenfeld, zt”l, the venerable gadol made a request of the Jewish official. “Please have warning signs affixed near all of the entrances to Har Habayis so that ignorant Jews will know not to enter the area and risk transgressing all of the many prohibitions involved. They could even be liable to kares unless we take steps to prevent such violations!”
In those years, the Jewish community was very careful with this prohibition and did not enter Har Habayis at all. Although there is documentary evidence that some Rishonim did enter certain permitted areas of the Har Habayis, later generations would not rely on this since there are conflicting shittos and there is too much of a possibility of error.
Sir Herbert requested in turn that Rav Sonnenfeld put his request in writing.
The Rav wrote, “I have taken the liberty to request permission of Your Honor to place signs in Hebrew, Yiddish, and Spanish to inform the Jewish people that we lack the ability to purify ourselves properly to enter this most holy place nowadays. It is therefore prohibited from the Torah for any Jew to enter the Har Habayis.”
When they left, the Rav’s escort asked his motives for this request since no Jews of the yishuv would ever consider doing such a thing.
Rav Sonnenfeld responded, “It is true that no one goes there now. However, what about Sir Herbert himself? As High Commissioner, isn’t it likely that he will be required at some time to go there? Once the signs are posted, they will provide him with an excuse to refuse to enter the area without offending the British authorities!”
 The overwhelming majority of authorities prohibit entry under any circumstances. This is not the time for a discussion of the relevant sources, but if anyone is interested please let me know.