There are signs outside the Haram in Makkah Shareef and Madina Shareef, which clearly instruct that there should be no begging. Outside our Masjid also, we have a sign, which reads, “No Begging.”
But this is outside the Masjid. There is no begging outside the Masjid and, indeed, Shariah discourages begging. The Hadith also tells us: “The upper [giving] hand is superior to the lower [taking] hand.”
So on this level, begging is not at all encouraged. It is disliked in Islam, unless the person is destitute and in dire need.
However, on another level, a Muslim must beg – but a Muslim must beg of only Allah Ta’ala. This is something beloved to Allah Ta’ala. Rasulullah (Sallallaahu 'alayhi wasallam) said: “There is nothing dearer to Allah than a servant making Dua to Him.”
Allah Ta’ala's treasures are unlimited. So, inside the Masjid, we beg of Allah Ta’ala.
Furthermore, we find that beggars teach us how to beg of Allah Ta’ala – especially in Makkah Shareef. We see how beggars follow us, and they will persist and insist in asking from us, to the extent of even catching the person’s garment. They even cry for something, for anything. …They just refuse to leave until something is given. They have that Yaqeen that the person they are begging from has something and will give if they persist.
These beggars outside the Haram Shareef are teaching us a lesson of how to beg of Allah Ta’ala, inside the Haram Shareef or whenever we are making Dua.
…Sadly, we do not consider who we are asking when we make Dua. As such, we make Dua casually, in a relaxed manner: legs are stretched out, leaning against a wall, and no effort is even made to raise the begging bowls of the hands. And we make a Dua in this laid-back, careless manner – and we say webegged of Allah Ta’ala. And we sometimes do not even have conviction that Allah Ta’ala will give and will do and will provide. …A far cry from the beggars who beg from human beings.
These beggars teach us to keep begging – to persist in asking, and to ask of Allah Ta’ala with full Yaqeen: ‘O Allah, there is no shortage in Your Treasures… You have unlimited treasures. Everything is in Your control… Grant us complete forgiveness…’
Nothing is difficult for Allah Ta’ala to do and Allah Ta’ala will do, when we ask sincerely.
May Allah Ta’ala grant us all the Taufeeq of raising our hands and asking of Him, with sincerity and with conviction.
 Sahih Bukhari / Sahih Muslim