It was the third message in recent weeks from al-Qaida figures concerning the massive floods that affected around 20 million people in Pakistan, signaling a concentrated campaign by the terror group to tap into anger over the flooding to rally support.
But while the earlier messages by subordinates were angry, urging followers to rise up, bin Laden took a softer, even humanitarian tone - apparently trying to broaden al-Qaida's appeal by presenting his group as a problem-solving protector of the poor.
"What governments spend on relief work is secondary to what they spend on armies," bin Laden says on the 11-minute tape titled "Reflections on the Method of Relief Work."
"If governments spent (on relief) only one percent of what is spent on armies, they would change the face of the world for poor people," he said.
The top al-Qaida leader said a new "well-funded" relief organization should be created to study Muslim regions near bodies of water to prevent future flooding, to create development projects in impoverished regions and to work on farming and agriculture to guarantee food security.
"The famine and drought in Africa that we see, and the flooding in Pakistan and other parts of the world, with thousands dead along with millions of refugees, that's why people with hearts should move quickly to save their brothers and sisters," he said.
He urged Muslim businessmen to develop unused agricultural land in Sudan - where bin Laden was based in the 1990s - to boost food security in case of disaster.
The audiotape was posted on Islamic militant websites, according to the U.S.-based SITE Intelligence Group, which monitors jihadi forums and provided a copy of the message. Its authenticity could not be independently confirmed, though the voice resembled that of bin Laden in confirmed messages by him. The tape is aired over a still photograph of a smiling bin Laden superimposed over a picture of a man distributing aid.
The United States and Pakistani officials have often expressed fears that militant groups in Pakistan could drum up support by exploiting frustration among Pakistanis who feel aid has not reached them quickly following the floods that swept through the country starting in late July.
International donors have pledged more than $800 million for flood relief in Pakistan, the bulk of it coming from the United States which has donated nearly $350 million. The United Nations last month hiked up its call for aid, seeking to raise $2 billion for Pakistan's flood victims, its largest humanitarian appeal ever.
Two earlier al-Qaida videos about the floods took a sharply militant tone.
In a video released last week, a U.S.-born al-Qaida spokesman, Adam Gadahn, urged Muslims in Pakistan to join Islamist militants fighting their nation's rulers, saying that Islamabad's "sluggish and halfhearted" response to recent floods showed it did not care for them.
Before that, al-Qaida's No. 2 leader, Ayman al-Zawahri, made a thinly veiled call on Pakistanis to rise up against their government over what he said was the "failure" of authorities there to provide relief to flood victims.
Bin Laden often takes a more elevated, philosophical stance than his deputies, aiming to present himself as a sort of elder statesman - opining, for example, on global warming in past messages. Still, in his last audiotape - released in March - he threatened retaliation if the U.S. executes Khalid Sheikh Mohammed, the self-professed architect of the Sept. 11, 2001 attacks.