لَوْلاَ الْهَوٰى لَمْ تُرِقْ دَمْعاً عَلىٰ طَلِلِ      وَلاَ أَرِقْتَ لِـذِكْرِ الْبَـانِ وَالْعَلَـمِ

5/5. If you had not fallen in love, you would not have shed tears at the ruins (of your beloved) nor would you have lost sleep due to the remembrance of the Baan (cypress tree) and High Mountain.

In the previous stanza, the friends and family members address him stating that his love is in fact fake. In this stanza, he explains the proof for declaring the addressee to be wrong.

Ruins: The Arabs had one manner of expressing love. Many people would live like nomads, moving from one place to another. After staying for some time in a certain place, love would be created in the residents of that area.
After some time, when the tents were relocated to another area, only the remnants and ruins would remain behind. Thereafter, the lovers would go to that place and cry, thinking of their beloveds. In this stanza, the reason for mentioning the ruins is that wherever Rasulullaah SallAllaahu Alayhi Wasallam went and then left that area, it is as though those places are ruins, even if people are residing there.
Since the beloved is not there, the place is in fact a ruin.

Ruins here can refer to:

a.) The house of Makkah Mukarramah which Rasulullaah SallAllaahu Alayhi Wasallam migrated from. As long as Rasulullaah SallAllaahu Alayhi Wasallam resided in Makkah Mukarramah, the land was populated. For this reason, an oath is taken in the Quraan Majeed (Balad verse 1-2). After leaving Makkah Mukarramah, it is as though the landis barren.

b.) All those places where Rasulullaah SallAllaahu Alayhi Wasallam resided and then left, whether it is in Makkah Mukarramah, Madinah Munawwarah, the places where wars took place, etc.

Baan can refer to:

a.) Any Cyprus tree which grows in Makkah Mukarramah

b.) A special tree close to Makkah Mukarramah where Rasulullaah SallAllaahu Alayhi Wasallam would go and discuss issues with the Sahaabah RadhiAllaahu Anhum.

‘Alam (high mountain) refers to:
A specific mountain in Makkah Mukarramah. Some state that this means the Mount of Abu Qubais, others have stated that it refers to Idham, whilst others have stated that it refers to the cave of Hiraa.

The most beloved place for a lover:

Moulana Rumi Rahimahullah writes that a beloved asked her lover, “You have travelled and seen many places. Which of these is most beloved to you?”
The lover answered, “The city in which my beloved resides is most beloved to me. As long as you are with me, I do not care where I live, even if I have to live in the depths of the ground.”

On thinking of the places where Rasulullaah SallAllaahu Alayhi Wasallam used to reside, the poet begins crying. Thinking of the mountain and tree where Rasulullaah SallAllaahu Alayhi Wasallam would go causes the poet insomnia.
Insomnia is caused because of lack of moisture in the body. Moisture causes sleep. When a lover cannot eat and drink, no moisture is formed in the body, and therefore one cannot sleep. In fact, when a lover thinks of his beloved, there is an increase of heat in the body.  

These are two proofs of love. If there was no love, then this would not have occurred.

Some scholars state that this stanza is indicating towards this poem of Majnoon,

أمرُّ على الدّيار ديار سلمى ... أقبّلُ ذا الجدارَ وذا الجدارا

وما حبُّ الدّيارِ شَغَفْنَ قلبي ... ولكنْ حبُّ منْ سكنَ الديارا

I pass by the houses, the houses of Layla.

 I kiss this wall and that wall.

 The love of the houses have not captured my heart, 

But rather the love of the one who resides in these houses.
(Diwaan Majnun wa Laylaa page 127)

To Be Continued

مَوْلَاىَ صَلِّ وَ سَلِّمْ دَائِمًا أَبَداً  عَلىٰ حَبِيْبِكَ خَيْرِ الْخَلْقِ كُلِّهِمِ