Ottoman Peiks & similar Persians & Mughals

The Ottomans had a bodyguard/messenger called a Peik (Peyk) who would march before the Sultan. They usually carried a small axe as in an illustration of a Peyk by Nicolas de Nicolay and could wear bells attached to garters & sash and carry a bottle of rosewater for refreshment.
Peyk is a Persian word meaning a message to a specified recipient.

Ottoman miniatures:
Sultan Suleiman the Magnificent during the Siege of Estolnibelgrad in Hungary, 1543
Sultan Suleiman the Magnificent during the campaign on Nachivan in the South Caucasus, 1554
Sultan Selim - riding between Kutahya and Belgrade, en route to join the Imperial Army
Three figures in Departure from the palace of the army for the war, Nusretname, 1578
The Ottoman Army at Tiflis, Nusretname, 1578

This position may have been from a wider cultural tradition.
Nicolas de Nicolay also illustrated a Peyk of the Persian nation.
Some Persian miniatures with a similar character:
The Old Woman complaining to Sultan Sanjar, from a 1539-43 Khamsa by Nizami
The Death of Zahhak from the Shahnama of Shah Tahmasp, c. 1522-1540
A royal usher from Dr. Kaempfer's Album of Persian Costumes and Animals

Mughal miniatures with a similar character:
Prince Riding Prancing Horse
Foray to Kuhat, from the Baburnama
Babur visiting the Urvah valley in Gwalior
Meeting between Babur and Sultan 'Ali Mirza near Samarqand
Babur and his army emerge from the Khwaja Didar Fort, Baburnama
1502, Babur advancing through the mountains to Kabul
Adham Khan pays homage to Akbar at Sarangpur, 1561, Akbarnama (upper left)
Flight of Sultan Bahadur During Humayun's Campaign in Gujarat, 1535, Akbarnama
Prince Akbar Hunting a Nilgae, c.1555 - 1560
Toda Mongke and His Mongol Horde, from a Chingiznama (History of Genghis Khan), painted 1596

Are these related to a Mongol practice?:
Hulagu and his envoy (ilci) leading his army against the castles of the Assassins includes a footman in front who seems to carry a paiza, a sign that identifies persons on official duty.

Index of Illustrations of Costume & Soldiers