Is this hadith, about paradise being promised to a person for guarding his tongue and private parts, not found in English version of Bukhari?

Is this hadith authentic and what is the explanation behind it?! حدثنا ‏ ‏محمد بن أبي بكر ‏ ‏حدثنا ‏ ‏عمر بن علي ‏ ‏ح ‏ ‏و حدثني ‏ ‏خليفة ‏ ‏حدثنا ‏ ‏عمر بن علي ‏ ‏حدثنا ‏ ‏أبو حازم ‏ ‏عن ‏ ‏سهل بن سعد الساعدي ‏ ‏قال النبي ‏ ‏صلى الله عليه وسلم ‏ ‏من توكل لي ما بين رجليه وما بين لحييه توكلت له بالجنة ‏ Muhammad ibn Abi Bakr, Umar ibn Ali narrated and told me Khalifa Umar ibn al-Ali told us told us Abu Hazim from Sahl bin Saad Al-Saadi: The Prophet peace be upon him said: Whoever entrusts to me what is between his legs and what is between his lips will be granted paradise. Sahih Bukhari 6309