Haarith bin Qais was also referred to as Haarith bin ‘Aytalah. ‘Aytalah was his mother’s name while his father’s name was Qais. He was also one of the people who would mock and taunt the Sahaabah of Rasulullah (sallallahu ‘alaihi wasallam).
He would often remark, “Muhammed (sallallahu ‘alaihi wasallam) has deceived his companions by leading them to believe in life after death.” He would say:
والله ما يهلكنا إلا الدهر
By Allah! Nothing but time destroys us.
When their mockery and scorn went beyond limits, Allah Ta‘ala revealed the following verses to comfort Rasulullah (sallallahu ‘alaihi wasallam):
فَاصۡدَعۡ بِمَا تُؤۡمَرُ وَ اَعۡرِضۡ عَنِ الۡمُشۡرِکِیۡنَ ﴿۹۴﴾ اِنَّا کَفَیۡنٰکَ الۡمُسۡتَہۡزِءِیۡنَ ﴿ۙ۹۵﴾
So openly proclaim (O Muhammed (sallallahu ‘alaihi wasallam)) what you have been commanded, and (if the disbelievers refuse to accept then) turn away from the disbelievers. Verily, We will suffice you against those who mock. (Surah Hijr v. 94-95)
(Extracted from Seeratul Mustafa 1/221-222)