Allah tells us how the disbelievers mocked the Messenger when they saw him.
This is like the Ayah,
[وَإِذَا رَآكَ
الَّذِينَ كَفَرُواْ إِن يَتَّخِذُونَكَ إِلاَّ هُزُواً]
(And when the disbelievers see you, they take you not except for mockery)
(21:36), which means that they tried to find faults and shortcomings in him.
Here Allah says:
[وَإِذَا رَأَوْكَ
إِن يَتَّخِذُونَكَ إِلاَّ هُزُواً أَهَـذَا الَّذِى بَعَثَ اللَّهُ رَسُولاً
]
(And when they see you, they treat you only in mockery (saying): "Is this the
one whom Allah has sent as a Messenger'') i.e., they said this by way of
belittling and trying to undermine him, so Allah put them in their place, and
said:
[وَلَقَدِ
اسْتُهْزِىءَ بِرُسُلٍ مِّن قَبْلِكَ]
(And indeed Messengers before you were mocked at) (6:10)
[إِن كَادَ
لَيُضِلُّنَا عَنْ ءَالِهَتِنَا]
(He would have nearly misled us from our gods,) They meant: `he nearly turned
us away from worshipping idols, and he would have done so, had we not been
patient and persevered in our ways.' So Allah said, warning and threatening
them:
[وَسَوْفَ
يَعْلَمُونَ حِينَ يَرَوْنَ الْعَذَابَ]
(And they will know, when they see the torment...)