Assalamualaikum ustaz. During the Friday sermon, I was very sleepy and nearly fell asleep. What should I do? Is it permissible for me to move to another location to overcome this matter? Hope for a suggestion.
Waalaikumussalam wrt. wbt.,
Alhamdulillah, praise and gratitude to Allah SWT for His countless blessings for us all. Praise and salutations to our beloved Prophet Muhammad PBUH, his family, companions, and all those who follow his footsteps until the Final day.
Basically, there are two general matters that makes a person considered to be lagha in his Friday. WE detailed it as the following:
There is a hadith of the Prophet PBUH which mentioned the prohibition against a person from talking during the sermon. From Abu Hurairah RA, the Prophet PBUH said:
إِذَا قُلْتَ لِصَاحِبِكَ يَوْمَ الجُمُعَةِ: أَنْصِتْ، وَالإِمَامُ يَخْطُبُ، فَقَدْ لَغَوْتَ
“On Friday, when the Imam is delivering the Khutbah (religious talk), if you say to your companion to keep quiet, then indeed you have committed a sin (error/something senseless).” 
Saidina Ali RA said, “Whoever did something senseless means he doesn’t receive anything for his Friday.” This means that he wouldn’t receive the advantages of Friday and hoped rewards from it. 
Scholars agreed that the afdhal (prioritized) is for a person to listen to the sermon of the imam quietly and attentively. This is prioritized over him busying himself with dhikrs alone, reciting the Quran or supplicating. 
Second: Actions or Movements of the Body
Any movement and action that will distract and make a person loses his focus from the sermon delivered will also make a person lagha. This is based on a narration from Abu Hurairah RA, where the Prophet PBUH said:
مَنْ تَوَضَّأَ فَأَحْسَنَ الْوُضُوءَ ثُمَّ أَتَى الْجُمُعَةَ فَاسْتَمَعَ وَأَنْصَتَ غُفِرَ لَهُ مَا بَيْنَهُ وَبَيْنَ الْجُمُعَةِ وَزِيَادَةُ ثَلاَثَةِ أَيَّامٍ وَمَنْ مَسَّ الْحَصَى فَقَدْ لَغَا
“If anyone performs ablution, doing it well, then comes to the Friday prayer, listens and keeps silent, his sins between that time and the next Friday will be forgiven him, with three days extra; but he who touches pebbles has caused an interruption (lagha).” 
According to the above hadith, it can be understood that the act of playing with pebbles when the khatib is delivering the sermon is prohibited and results in its doer becoming lagha. This is widened to other actions that cause a person to lose focus when listening to the sermon. For example, playing with the phone, sleeping, eating and drinking without any reason and others.
Acts that Help to Increase One’s Focus When Listening to the Sermon
However, there are exceptions for actions that help to increase one’s focus during the sermon. Especially if the act could remove one’s sleepiness during the sermon. The support for this is a narration from Ibn Umar R.Anhuma, Rasullullah PBUH said:
إِذَا نَعَسَ أَحَدُكُمْ وَهُوَ فِي الْمَسْجِدِ فَلْيَتَحَوَّلْ مِنْ مَجْلِسِهِ ذَلِكَ إِلَى غَيْرِهِ
“When any of you dozes in the mosque (on Friday), he should change his place.” 
This hadith shows that not all movements are prohibited during the sermon. However, actions such as moving from one place to another are permissible and even sunnah with the purpose to avoid sleepiness and continue to listen attentively to the sermon.
The following are wisdoms to the act of changing or moving seats:
- The movement could remove the sleepiness.
- There is shaytan at the place which makes him sleepy.
Two of these wisdoms are stated by al-Sayyid Muhammad Siddiq Hasan in his book al-Din al-Khalis (4/145-146).
Thus, the actions and movements such as these aren’t prohibited nor is it considered lagha. Moreover, it is encouraged and a sunnah.
Here we state, a person who is sleepy during the sermon is sunnah to change his set or move to another place in the mosque.
However, considering the situation we’re in where usually on the day all the saf is filled during the sermon, then it isn’t necessary for the person to move to another place if he’s sleepy because this would disturb the other congregants. However, he can do other actions such as squeezing his neck, body or others to ease his sleepiness.
Hopefully, this explanation will give a clear understanding to us all in religion. Amin.
 Narrated by al-Bukhari (934)
 See al-Mu`tamad, 1/533
 See Fath al-Bari, 8/274
 Narrated by Muslim (857)
 Narrated by Abu Daud (1119)