There is, however, room for further consideration in both issues.

As for the first issue—namely, alerting someone to stand with him—the correct view is that he is not entitled to do so. If he alerts someone, he puts him in an awkward position; moreover, this may fall under blameworthy asking, since the person he alerts will thereby have done him a favor for which he will feel indebted. Furthermore, if this door were opened, people might be inconvenienced: whenever someone came and found no one to stand with him, we would tell him, “Alert someone to stand with you.” Nor is this established from the practice of the Companions or the Followers.

As for the second issue, the correct view is that the person alerted is not required to step back with him. For if we were to say that he must step back, we would have to say that if he did not do so, he would be sinful. Yet Allah the Exalted says: “No bearer of burdens will bear the burden of another.” [al-Isra’ 17:15] Just as I am not required to buy water for someone who cannot find water for ablution, nor am I required to procure water for him, the same applies here. Completing acts of worship is not the responsibility of anyone other than the worshipper himself; acts of worship are incumbent upon the worshipper himself, whereas others are free of responsibility for them.

So what should he do if he is not permitted to alert someone to stand with him?

The answer is: according to the madhhab, he should wait until Allah makes it easy for someone to stand with him, or else pray alone.

The correct view is that he should pray alone behind the row, following the imam. (1)

The evidence for this is as follows: