Hadith: O people, do not trouble yourselves too much. He Whom you are calling is not deaf or absent. Verily, He is with you, He is All-Hearing and Ever Near

عن أبي موسى الأشعري رضي الله عنه قال: كنا مع النبي صلى الله عليه وسلم في سفر، فكنا إذا أشْرَفْنَا على واد هَلَّلْنَا وكبَّرْنَا وارتفعت أصواتنا، فقال النبي صلى الله عليه وسلم : «يا أيها الناس، ارْبَعُوا على أنفسكم، فإنكم لا تدعون أصمَّ ولا غائباً، إنَّه معكم، إنَّه سميع قريب».
[صحيح] - [متفق عليه، واللفظ للبخاري]

Abu Mūsa al-Ash‘ari (may Allah be pleased with him) reported: We were on a journey with the Prophet (may Allah's peace and blessings be upon him) and whenever we ascended from a valley we would say "there is no god but Allah" and "Allah is the Greatest" and we would raise our voices. So the Prophet (may Allah's peace and blessings be upon him) said: "O people, do not trouble yourselves too much. He Whom you are calling is not deaf or absent. Verily, He is with you, He is All-Hearing and Ever Near."
[Authentic hadith] - [Al-Bukhari and Muslim. This is the wording of Al-Bukhari]

Explanation

The Hadīth of Abu Mūsa al-Ash‘ari (may Allah be pleased with him) states that they were with the Prophet (may Allah's peace and blessings be upon him) on a journey. They would say "there is no god but Allah" and "Allah is the Greatest" in a loud voice." So, the Prophet (may Allah's peace and blessings be upon him) said: "O people, do not trouble yourselves too much", meaning take it easy and do not burden yourselves with raising your voices, because the One you are calling is not deaf or absent. You are calling Allah, the Almighty, Who is All-Hearing, Answering your call, and Near to all. He has no need seeing you burdening yourselves with raising your voices when glorifying, praising, or exalting Him. This is because Allah, the Exalted, hears and sees everything. He is Near and encompasses everything in spite of the fact that He is above the heavens. The Prophet (may Allah's peace and blessings be upon him) highlights that Allah, the Almighty, is completely Hearing, Seeing, and Near as He possesses the highest level of all perfect attributes. The very hidden movement never escapes His hearing. He hears the crawling of the ant on the black rock in the darkness of night, and even what is quieter than that. Similarly, no screen covers anything from His sight. He hears your tones, the sounds of your breath, and any word you utter. Allah sees your movements. He is with you and Near to those who call Him. He is also with all of His creatures in a away that He knows and encompasses them. The whole creation is in His grasp. Yet, He is above His throne and high above all of His creation. No secrets of the creation are hidden from Him, whatever it may be. Hearing and Seeing are two attributes affirmed to Allah, the Exalted, in a way that befits His Majesty without asking how, resembling Allah to any of His creation, or distorting the wording or the meaning.